Refrigerating apparatus



Oct. 18, 1938. D. H. REEVES 5 REFRIGERATING APPARATUS Filed July 12, 1935 2 Sheets-Sheet l E IN VENTOR.

Oct. is, 1938.

D. H. REEVES 2,133,361

REFRIGERATING APPARATUS Filed July 12, 1935 2 Sheets-Sheet 2 ilIlIL v ATTORNEYS Patented Oct. 1 1938 I I 2,133,361

UNITED-- STATES PATENT OFFICE REFRIGERATING APPARATUS Donald H. Reeves, Dayton, Ohio, assignor to General Motors Corporation, Dayton, Ohio, a corporation of Delaware Application July 12, 1935, Serial No. 31,066

8 Claims. (Cl. 62-8) This invention relates to refrigerating apparadisclosed a bed cooler having a low curtain structus and more particularly to control means ture extending about eighteen inches above the therefor; I mattress and provided with a fabric envelope at In the cooling of beds by refrigerating systems, one end into which cooled air is forced to cause it is deemed undesirable to start and stop the rethe cooled air to pass slowly through the fabric 5 frigerating system in order to control the cooling wall of the envelope into the curtained enclosure. of the bed. In the first place, this would provide This air'is supplied by an air cooler comprising considerable and rapid changes in the temperaa comp yp r f i er in y t m pr ture within the bedand it would also be rather vided with an improved form of valve in the suc- 10 undesirable because it would provide intermittent tion line for controlling its'capacity. This valve 10 periods of quiet and noise particularly the addiis provided with a metering needle and is opertional noise when starting and sometimes when ated by the liquid eXpanBion of Oil Which s bstopping, which would tend to prevent sleep. On stantially independent of pressure. The oil which the other hand, if the refrigerating system is does the controlling is contained in a compara-' l5 permitted to operate continuously, it will, if ell tively large metal bulb or chamber provided with made, provide a low steady hum which is notoban adjustable displacing means for adjustin t e jectionable. temperature at which the valve operates.

It is, therefore, an object of my invention to In he s n f rm of y inven ion, I have provide an improved mean for controlling th shown a domestic electric refrigerator provided temperature of a. continuously operating refrigerwith an adjustable control switch having oil as its 20 ating system and particularly one which may be thermal expehsible fillide Controlling D readily controlled as to the temperature protion of this Oil is contained in a comparatively due d, large metal bulb or chamber provided with a It is another object of my invention to prol q plac ng means which .inay be used o vide an improved suction line control valve for a control the temperature at Which the Sw 0D- 25 refrigerating system which will accurately meter eratesthe flow of refrigerant through the suction line Referring HOW to the drawings, d more p according to certain temperatureg ticularly to Fig. 1, there is shown a bed general- It is still another object of my invention to y n d y the reference character 20 p provide an improved control means for a. refrigvided with a mattress 22 and a curtained enclo- 30 erating system which employs th expansion of sure 24 extending upwardly about eighteen inches oil to control the temperature of the refrigerfrom the D of the mattress and having its owating apparatu5 er edges tucked beneath the mattress. This cur- Furth objects d advantages of th present tained enclosure is provided with elastic gathered invention will be apparent from the'following depor s 26 a d po s in the hem at the four 35 scription, reference being had to the accompanycorners which are held by vertical rods or standing drawings, wherein a preferred form of the ards 28 having their bases resting upon the floor present invention is clearly shown. and held down by the legs of the bed. At the In the drawings: head end of the bed there is provided an envelope Fig. 1 isa perspective view of a bed cooler em- 30 having a fabric wall on its inner side. This 40 bodying my invention including a diagrammatic envelope is connected by a duct 32 to an air coolrefrigerating air cooling system for'the bed; ing unit 34 shown diagrammatically which in- Fig. 2 is a sectional view of the suction line concludes a cooling chamber 36 and a refrigerant trol valve of the refrigerating system shown in liquefying chamber 38.

Fig. 1; Within the refrigerant liquefying chamber 38 45 Fig. 3 is a fragmentary view ofa portion of the there is shown a compressor 40 driven by an elecoil displacement mechanism t en a n t e lines trio mtor 2 for compressing the refrigerant and I--3 of Fig. 2; 1 for forwarding the compressed refrigerant to a Fig. 4 shows a fragmentary portion of a docondenser 44 where the compressed refrigerant is mestic refrigerator provided with a refrigerating liquefied and collected in a receiver 46. From the 50 system and another form of my control means; receiver 46 the liquid refrigerant is forwarded and t through a supply conduit 48 to an automaticex- Fig. 5 is an enlarged view, partly in section, of pansion valve 50 located in the chamber 36 which the control means shown in Fig. 4. controls the flow of liquid refrigerant to the air 65 As the first embodiment of my invention, I have cooling evaporating means 52 also located Within 55 fabric wall of the envelope into the curtained enclosure where it tends to seek the bottom of the enclosure so as to provide a cool and comfortable environment for the occupant of the bed. The evaporating means 52 not only cools the air, but also condenses moisture from the air and thereby dehumidifies the air. This moisture is collected in a receptacle 58. The evaporated refrigerant from the evaporating means is returned to the compressor through the suction line 60 which is provided with my improved suction line control valve 62 located in the compartment 36 and connected by tubing 64 to a thermostatic bulb 66 located near the air inlet of the.cham-. ber 36 so as to be responsive to room temperature.

The unit may be started at any timev by closing the manual switch 68 which starts the operation of both the compressor motor 32 and the electric fan 56 to cool the air and to force the cooled air through the porous fabric wall of the envelope into the curtained enclosure of the bed. It is, of course, necessary that the temperature of the air supplied to the bed be accurately regulated so as to provide a comfortable environment of the proper temperature and humidity for the occupant of the bed. This is done entirely by my improved suction line control valve. This valve is so formed that at its normal Setting, it will begin to close when the room temperature drops below approximately F. It will be completely closed at approximately 82 F. room temperature. Between these two points, the amount of valve opening is and must be accurately regulated. I also provide a manually selective means for raising or lowering these temperatures about 6.

In suction line control valves, there has been considerable difliculty in providing these regulations. This is to a considerable extent due to the fact that varying pressures exist in such a valve and such varying pressures have always affected the operation of the valve and caused it to operate difierently from its setting. The reason for this has been that the fluids used to control a valve have been afiected in a marked manner by pressure, and since these fluids were to a certain extent subject to the pressure within the suction line, the operating characteristics changed according to the pressure within the suction line.

In order to overcome this, I employ the liquid expansion of a fluid which does not change its thermal expanding characteristics to any substantial degree with a change in pressure thereof. For this purpose, I use lubricating oil having a viscosity of which has been dehydrated and deaerated by heat and vacuum to remove any traces of moisture and gases from the oil. Of course, other liquids such as turpentine may. be used. In Fig. 2 there is shown the valve 62 having a valve body I0 with an entrance portion .12

connecting with the evaporating means 52 and an exit portion 14 connected to the suction side of the compressor. The entrance portion 12 is provided with a valve seat I6 which cooperates with this flow at the proper rate so as to provide the proper increases in the amount of opening according to the thermal expansion of the oil so that the temperature of the evaporating means is controlled as desired.

The needle valve has a reduced portion 84 beneath the needle portion 82 and a shank portion 86 which fits'within a guide portion 88 in the valve body. The end of this shank is provided with a threaded portion of reduced diameer which is threaded into the end plate 90 forming the end plate of a bellows 92 sealed at its opposite end to an annular projection 94 extending from the valve guide 88. This bellows is surrounded by a heavy metal cap or cup 96 which is sealed to a rim 98 projecting from the valve guide and which receives at its closed end portion the one end of the connecting tube 64. The other end of the connecting tube 64 extends through the wall of a heavy inverted cup-shaped member IOI provided with an end plate H33 which closes its lower end. At the side opposite the entrance portion of the tube 84 there is provided a charging tube I05 for charging the thermal control system with oil or other suitable The cup-shaped member IOI is also provided with a liquid displacement mechanism including a bellows IIl'I sealed at its lower end to a bellows plate I539 and the end plate I03 and sealed at its upper end to a bellows plate I I I. The upper bellows plate III is provided with a stop pin H3 which is adapted to engage the closed end of the cup-shaped member IM to limit the expansion of the bellows or the upward movement of the plate III. This stop pin H3 is sealed to the upper end plate I I I and extends through into the interior of the bellows and has a spring follower I I5 threaded upon its reduced lower end portion. This spring follower H5 is held tightlyagainst the upper flange II I of'a spring cage I I9 by a fifty pound compression coil spring IN. This cage is provided with a lower flange I23 which supports the lower end of this spring. This cage at its lower end is also provided with a threaded aperture I25 which receives an adjusting screw I21, which is held in place by a shoulder which engages the outer plate I29 to prevent the outa pair of pins I3I which engage slots I33 in the side of the cage to prevent the rotation of the cage. The head of the set screw I21 is normally provided with an indicating and manipulating device which cooperates with the dial to provide a convenient selective adjustment for controlling the temperature produced by the refrigerating system. This set screw I27 operates by moving the spring cage '9 upwardly or downwardly so as to move the upper bellows plate III upwardly or downwardly to displace the oil in the system and to force it to move the bellows 92 of the valve so as to move the valve to a difierent position. The upper bellows plate III of the spring cage III! will operate together at all times excepting when the pin II3 should engage the upper wall of the cup-shaped member IM or when the bellows encounters a pressure greater than the force of the spring l2l.

The bellows 92 contains refrigerant substane tially at the pressure of the suction linewhich tends to hold the valve 16 in closed position.

When the oil in the thermostatic bulb 66 is cool,

there is a vacuum existing in the oil control system which permits the refrigerant pressure within the bellows 92 to hold the valve 16 tightly closed. As the oil grows warmer, it expands and exerts force upon the outside of the bellows 92 to move the valve 16 off its seat, and the higher the temperature, the greater the expansion of the oil and the wider the valve and valve needle passage is opened without being substantially affected by the refrigerant pressure within the bellows 92. Thus, I have provided a suction line control valve for the refrigerating system of a bed cooler which is not substantially affected by the pressures within the refrigerating sys-' tem and which will accurately control the temperatures provided by the system to keep the atmosphere within the bed enclosure comfortable.

In Fig. 4 I have shown a domestic electric refrigerator including a cabinet 228 containing a food compartment 222 provided with a refrigerant evaporating means 224 containing ice trays 226 and provided with an adjustable switch means 228 connected by a tube 266 to a thermostatic bulb 268; The evaporating means 224 is supplied with liquid refrigerant by a liquefying apparatus including a compressor 234, driven by an electric motor 236 for withdrawing evaporated refrigerant from the evaporating means through the suction line 238, compressing. the evaporated refrigerant and forwarding the compressed refrigerant to acondenser 240 where the compressed refrigerant is liquefied and collected in a receiver 242. From the receiver 242, the liquid refrigerant passes through a small capillary tube 244 which controls the flow of liquid refrigerant. into the evaporating means'224. The switch 228 is connected in the electric motor circuit 246 in series with the electric motor 236 in order to control the operation of the system according to the temperature of the air within the food compartment 222.

Referring now more particularly to Fig. 5, the

[switch is shown with an operating bellows 248 which operates a primary lever 25!! and a double toggle snap acting switch mechanism 252 which cntrols the opening and closing of the switch contacts 254 to control the operation of thecompressor motor 236, The primary lever 250 is held in operative relation with the bellows 248 by a tension spring 256 whose tension may be controlled by a selective adjusting mechanism including a temperature control knob 258. The switch is also provided with a single cycle loading mechanism which includes a finger manipulator 266 connected to a toggle mechanism 262 provided with a roller 264 adapted to bear upon the primary lever 258 to load the bellows for a single cycle in order to raise the temperature of the evaporating means for a single cycle. The primary bellows 248 is connected by th tube 266'to the thermostatic bulb 268 similar 'to the thermostatic bulb lnl in Fig. 2. This thermostatic bulb contains a bellows 218 whose extension is controlled by a set screw 212 which controls the volume in the thermostatic bulb, the connecting tube and the bellows 248. This closed system is charged through the charging-tube 214.

This closed system may be charged either with a volatile fluid or with a thermally expansible liquid such as oil.- In the latter case, the operating characteristics of the switch will be substantially entirely controlled by the deplacement of the bellows 210. In such a case, it is desirable to provide the set screw 212 with a finger manipulator like the finger manipulator 258 and a suitable dial for indicating the selection which may be obtained by its adjustment. By the use of oil or other liquid expansible fluid in connection with such a switch, the operating characteristics may be made very accurate and may be varied within rather wide limits by properly proportioning the size of the elements in the closed system including the bellows 248, the connecting tube and the thermostatic bulb 268.

While the form of embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adpoted, all coming within the scope of theclaims which follow.

What is claimed is as follows:

1. Refrigerating apparatus including an evaporating means, a liquefying means for supplying liquid refrigerant to and for withdrawing evaporated refrigerant from the evaporating means,

a valve for controlling the withdrawal of refrigerant from the evaporating means, a metering means in series with the valve for providing a. throttling of the flow of refrigerant when the valve is open, and temperature responsive means for operating said valve and said metering means for controlling the withdrawal of refrigerant according to temperatures.

2 Refrigerating apparatus including an evaporating means, a liquefying means for supplying liquid refrigerant to and for withdrawing evaporated refrigerant from the evaporating means, a valve means for controlling the withdrawal of refrigerant from the evaporating means, 2. diaphragm means connected to the valve means,

said diaphragm means being exposed on one side to the refrigerant controlled by the valve means, an enclosure for the other side of said diaphragm means, said enclosure containing a liquid in contact with the diaphragm means, said liquid having a boiling point sufficiently high to keep it in a liquid state below F. "s

3. Refrigerating apparatus including an evaporating means, a liquefying means for supplying liquid refrigerant to and for withdrawing evaporated refrigerant from the evaporating means, a valve means for controlling the withdrawal of refrigerant from the evaporating means, 9. diaphragm means connected to the valve means, said diaphragm means being exposed on one side to the refrigerant controlled by the valve means, an enclosure for the other side of said diaphragm means, a. tube connected to said enclosure, a bulb connected to said tube, said enclosure, said tube and said bulb containing a liquid having a boiling point sufiiciently high to keep it in a liquid state below 120 F.

4. Refrigerating apparatus including an evaporating means, a liquefying means for supplying liquid refrigerant to and for withdrawing evaporated refrigerant from the evaporating means, a valve means for controlling the withdrawal of refrigerant from theevaporating means, a diaphragm means connected to the valve means, said diaphragm means being exposed on one side to the refrigerant controlled by the valve means, an enclosure for the other side'of said diaphragm means, a tube connected to said enclosure, a bulb connected to said tube, said enclosure, said tube 5. Refrigerating apparatus including an evaporating means, a liquefying means for supplying liquid refrigerant to and for withdrawing evaporated refrigerant from the evaporating means, a valve for controlling the circulation of refrigerant through the evaporating means, means forming a flexible chamber operatively connected to the valve means, said means forming a flexible chamber being located in heat conducting relationship to the refrigerant controlled by the valve means, and said flexible chamber containing a liquid having a boiling point sufficiently high to keep it in a liquid state and having a congealing point sufliciently low to keep it in a liquid state during all conditions of normal use and operation.

6. Refrigerating apparatus including an evaporating means, a liquefying means for supplying liquid refrigerant to and for withdrawing evaporated refrigerant from the evaporating means, a valve means for controlling the circulation of refrigerant-through the evaporating means, means forming a flexible chamber for operating the valve means, said means forming a flexible means being in heat conducting relationship with the refrigerant controlled by the valve means, a tubular means connected to said flexible chamber, said tubular means being sealed at the end opposite flexible chamber, said flexible chamber and said tubular means containing a liquid having a boiling point sufllciently high to keep it in. a liquid state and having a congealing point sufllciently low to keep it in a liquid state during all conditions of normal use and operation.

7. Refrigerating apparatus including an evaporating means, a liquefying means for supplying liquid refrigerant to and for withdrawing evaporated refrigerant from the evaporating means, a valve for controlling the circulation of refrigera nt through the evaporating means, means forming a flexible chamber operatively connected to the valve means, said means forming a flexible chamber being located in heat conducting relaticnship to the refrigerant controlled by the valve means, and said flexible chamber containing a liquid having a boiling point sufliciently high to keep it in a liquid state below 120 F. and having a congealing point sufllciently low to keep it in a liquid state above F.

8. Refrigerating apparatus including an evapcrating means, a liquefying means for supplying liquid refrigerant to and for withdrawing evaporated refrigerant from the evaporating means, a valve means for controlling the circulation of refrigerant through the evaporating means, means forming a flexible chamber for operating the valve means, said means forming a flexible means being in heat conducting relationship with the refrigerant controlled by the valve means, a tubular means connected to said flexible chamber, said tubular means being sealed at the end opposite flexible chamber, said flexible chamber and said tubular means containing a liquid having a boiling point sufliciently high to keep it in a liquid state below 120 F. and having a congealing point. sufilciently low to keep it in a liquid state above 0 F.

DONALD E. REEVES. 

